Technical Field
The present disclosure relates to the field of display technologies, and particularly to a display panel and a display device.
Description of the Related Art
With development of the display technology, a display has been widely used in various electronic devices gradually. Diversification of the display also becomes an important characteristic of the electronic devices. Transparent display screen is a new display screen and has a certain light transmittance, so that when displaying a signal, image information may be displayed on the display screen, and when no signal is displayed, the background behind the display screen may be viewed through the display screen. Recently, a flexible and transparent display screen that is formed by a flexible substrate is also proposed based on the transparent display. The flexible and transparent display screen has characteristics including light weight, thin thickness, impact resistance, flexibility, transparence and the like, and may not only be used for common display of a graphic signal but also be mounted on a surface of a non-planar object that is needed to provide transparent display. For example, the flexible and transparent display screen may be mounted on a windshield glass of a vehicle, a transparent advertising screen or the like. As the flexible and transparent display screen further endows a transparent display screen with flexibility, the transparent display screen will be more widely used in future applications.
When using a transparent display screen, the light transmittance of the transparent display screen often needs to be adjusted according to use environment. For example, when the transparent display screen is only used for display, light emitted from the transparent display screen and nature light passing through the same both enter human eyes, which causes a contrast of an image displayed by the transparent display screen to be decreased. In this case, the light transmittance of the transparent display screen needs to be adjusted to be low. As a further example, in a case where a transparent display screen is mounted on a windshield glass of a vehicle, the light transmittance of the transparent display screen needs to be adjusted to be low when displaying, and the light transmittance will be adjusted to be high so that a better viewing field can be obtained when the vehicle is travelling. However, display device in prior art has a constant light transmittance after manufactured and is not capable of adjusting its light transmittance. Therefore, it is an urgent problem for those skilled in the art to adjust a light transmittance of a display device.